Below mentioned code gives AttributeError beacuse of self.f() and when I re-write self.f() as f(self) error disappers why is it so?

Question

In the Below code Why can't I use self.f() to refer to secret method which is in A class

def check(f):
    def checking(self):
       print("Before secret method")
       self.f()
       print("After secret method")
    return checking
class A:
    @check
    def secret(self):
        print("Welcome to secret method")
a = A()
a.secret()

because `f` is not an attribute of `A`. `f`, on the other hand , is a variable that refers to the function you decorated, thus `f(self)` will work. — juanpa.arrivillaga, Jul 26 '20 at 08:08
[how-does-the-property-decorator-work](https://stackoverflow.com/questions/17330160/how-does-the-property-decorator-work) - extensive discussion on how decorators work in the accepted answer. — Patrick Artner, Jul 26 '20 at 08:13

score 0 · Answer 1 · answered Jul 26 '20 at 08:35

0

You are treating "self" as an object of class A by your invocation style, which it isn't. It refers to instance of class A, which is why f(self) works, as the method "secret" requires an instance of class A.

answered Jul 26 '20 at 08:35

Himanshu Jagtap

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U can't have an object itself u will just get a reference which points to object of class A. Then why can't I use self.f() to invoke secret method instead of f(self) – Santhosh Jul 26 '20 at 08:44
I think you should look at what instances and objects are in Python. Alternatively you can use simple degugging skills to uncover what that "self" refers to. – Himanshu Jagtap Jul 26 '20 at 08:51

Below mentioned code gives AttributeError beacuse of self.f() and when I re-write self.f() as f(self) error disappers why is it so?

1 Answers1